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Adjusted and Homogenized Canadian Climate Data (AHCCD)

This web site provides adjusted and homogenized climate data for many climatological stations in Canada. These data were created for use in climate research including climate change studies. They incorporate a number of adjustments applied to the original station data to address shifts due to changes in instruments and in observing procedures. Sometimes the observations from several stations were joined to generate a long time series.

These data are not the official Meteorological Service of Canada in situ station records and therefore should not be used for legal purposes. The official records can be obtained at the National Climate Data and Information Archive.

Users are strongly cautioned to determine the data suitability for their application. They should also be aware that ongoing research on adjustment techniques may result in future revisions of the datasets. The datasets are updated annually with the most recent data.

The adjusted and homogenized data are provided for four climate elements: